Newer versions of the FiveM (after mid December) are causing this error, i have tried 3 different machines (Windows Server 2012 & 2016 and Ubuntu 16) using different networks and i still got this error, it happens with 80% of the players.
This error occurs only when player is downloading the resources for the first time and also it don’t happens on localhost.
Screenshot: https://cdn.discordapp.com/attachments/270064750384250882/571582109555228673/unknown.png
I have tried to give full permissions to cache folder, disable firewall and use different versions after the 936 version (The latest version that don’t have this issue on Windows) but i had no success on it.
On Linux i don’t know the exact version that this error started to appear.